Parts Needed to Add a 7-Way Trailer Connector to a 2003 Ford F-150 without Factory Tow Package

Question:

My 2003 F150 Supercrew has the 4-way wiring harness. The truck did not come with a hitch, I have installed a hitch, and now want to add the 7-way connector to tow my boat. My boat has the 5-way blade includes the 5th pole for reverse to lock out to the brake assist. Will the 118242 be able to be installed on my truck and function properly eventhough I do not have the factory installed 7-way wiring?

asked by: Jack

Expert Reply:

If your 2003 Ford F-150 came with a factory installed 4-Way wiring harness, you can use the Ford Replacement OEM Tow Package Wiring Harness, # 118242. I have included a link to the installation instructions and a video showing a typical installation.

Once you have installed this harness into the factory connector under the truck, and inserted the fuses and relays where needed, the 7-Way should be fully functional. You will need to check the center pin with a circuit tester like # PTW2993, to determine if it is connected to the reverse light circuit. If not, you will need to sever the wire that goes to the center pin and connect it to a reverse light wire.

You would then need an adapter, like # 37385, to go from the 7-Way on the truck to the 5-Way flat on the trailer.

If the truck did not come with the 4-Way flat from the factory, it may not be compatible with the 118242 harness and you would instead need to install a 4 and 7-Way installation kit, # ETBC7. The purple wire on this kit would need to go to the reverse light circuit. An adapter will still be needed. I have included a link to an FAQ article on the ETBC7 for you to view.